My site has been having issues with speed. It is very slow at the moment (as no caching is installed). I would normally use WP Super Cache, but it conflicts with the slider. I also tried W3 Total Cache, but it didn’t have any difference at all. Is there a reason WP Super Cache conflicts? And I guess more importantly, is there a way to get caching to work properly on the site?

As far as I know WooComerce does not support SuperCache but it works with W3TC. I’d try to deactivate all third party plugins (except woocommerce of course) and check if this improves the loading times.